Secured the canopy on the tip-up frame and aligned with sides of frame, marked and used the die-cutter to remove between 1/4" and 1/8".
Used the side of the disc to 'dress' the plex slightly. Removed the canopy, filed, sanded and scraped the edges to avoid stress cracks during movement.
There is still a little bit of material that 'appears' to be excess, but will have to adjust the edges cautiously to avoid removal of too much.
Reviewed the details and notes of Dwg 51 and manual.